Energy from Fleischmann-Pons experiments: How does it work? Peter L. Hagelstein Research Laboratory of Electronics Massachusetts Institute of Technology.

Energy from Fleischmann-Pons experiments: How does it work?

Peter L. Hagelstein

Research Laboratory of ElectronicsMassachusetts Institute of Technology

Outline

•Relevant experimental results

•Constraint on energetic particle emission

•Fractionation of a large quantum

•Coherent energy exchange

•Two-laser experiment

•Karabut experiment

•Proposed mechanism

•Conclusions

Electrochemical cell

Excess energy in F&P expt

M Fleischmann et al, J Electroanalytical Chem 287 293 (1990)

4 MJ observed during 80 hours

Get 1.2 kJ for detonation of equivalent cathode volume (0.157 cc) of TNT

Effect not chemistry!

But why no support for the technology?

•Experiments point to new disruptive technology

•No place in nuclear physics, condensed matter physics for excess heat effect in Fleischmann-Pons experiment

•If known physics rules out effect, easy to argue that experimental error involved

•No support available for research and development on new technology deemed inconsistent with known physics

•Clarification of mechanism could help move things forward

Constraints on energetic 4He

Observations of 4He correlated with excess energy are consistent with a Q value (energy/He atom ratio) near 24 MeV

Important since mass difference between two deuterons and 4He is 24 MeV

2M[d]c2 – M[4He]c2 = 23.85 MeV

If we suppose a reaction of the form

Then we could gain information about what X is by measuring the kinetic energy of the 4He

4 He 23.85 MeVd d X X

How to measure energy?

•4He doesn’t go very far, and loses energy in PdD, D2O

•Hard to detect directly

•Propose indirect detection! When 4He hits deuterons can get primary and secondary neutrons

•And neutrons can be measured outside of the cell

•But wait, neutron measurements have been done on cells producing excess power!

Yield/energy for secondary neutrons

E (keV)

4 5 6 7 8 9 20 3010

Y/E

(

n/J)

0.001

0.01

0.1

1

Ue = 800 eV

Ue = 0 eV

E (keV)

4 5 6 7 8 9 20 3010

Y/E

(

n/J)

0.001

0.01

0.1

1Klein (1990)

E (keV)

4 5 6 7 8 9 20 3010

Y/E

(

n/J)

0.001

0.01

0.1

1

Gozzi (1994)

Klein (1990)

E (keV)

4 5 6 7 8 9 20 3010

Y/E

(

n/J)

0.001

0.01

0.1

1

Wolf (1990)Gozzi (1994)

Klein (1990)

E (keV)

4 5 6 7 8 9 20 3010

Y/E

(

n/J)

0.001

0.01

0.1

1

Takahashi (1993)Wolf (1990)

Gozzi (1994)

Klein (1990)

E (keV)

4 5 6 7 8 9 20 3010

Y/E

(

n/J)

0.001

0.01

0.1

1

Scott (1990)Takahashi (1993)

Wolf (1990)Gozzi (1994)

Klein (1990)

P. L. Hagelstein, Naturwissenschaften (2010)

What can we conclude?

•4He is born with a very low energy (less than 20 keV out of 24 MeV); result similar for upper energy of t in tritium production (less than 12 keV)

•Can rule out all Rutherford picture reactions with two-body final states (lowest 4He energy is about 76 keV for recoil with gamma or electron)

•If we add the practical constraint that energetic electrons and gammas would have been detected if created in amounts commensurate with the energy produced, then the constraint is much more severe

•If 24 MeV shared with deuterons, then sharing must involve more than 24,000 deuterons to be consistent with upper limit near 0.01 neutron/J

•Can rule out all Rutherford-picture mechanisms as inconsistent with experiment

Impact on theory

•This result has a dramatic impact on theory!

•Can rule out nearly all proposals, as only a few can be consistent with these constraints

•Only three approaches left:

1)Transfer reaction energy to condensed matter mode

2)Find new mechanism to slow down energetic MeV particles

without observable products

3)Find new mechanism for collective reaction that shares

energy with more than 24,000 nearby deuterons

The theoretical problem

•Nuclear system involves large (MeV) energy quanta

•Condensed matter system involves small (meV) energy quanta

•Not easy to exchange energy coherently between systems with mismatched energy quanta

•But experiments seem to indicate that it happens

New model for fractionation of a large quantum

Two-level systems

Macroscopic

excited mode

0

E

0 E Loss near E

Lossy spin-boson model:

Letts 2-laser experiment

D. Letts, D. Cravens, and P.L. Hagelstein, LENR Sourcebook Volume 2, ACS: Washington DC. p. 81-93 (2009).

Excess power with 2 lasers

t (min)

0 200 400 600 800

Pxs

(m

W)

0

100

200

300

lasers on

In single laser experiments, excess heat turns off when laser turns off; in two-laser experiments, excess heat stays on

What oscillator modes?

Results from dual laser experiments of Letts, J Cond. Mat. Nucl. Sci. 3 59,77 (2010)

f (THz)

0 5 10 15 20 25 30

Pxs

(m

W)

0

50

100

150

200

250

300

Dispersion curve for PdD

Operation was predicted on compressional modes with zero group velocity f

(TH

z)

0

2

4

6

8

10

12

14

16

X K L

[100] [110] [111]

PdD

Coherent energy exchange between phonons and nuclei

•Can we study effect in isolation?

•Excite compressional vibrational mode strongly

•Coherent energy exchange between mode and nuclei

•Would be easiest for lowest energy nuclear excitation

•If interaction with mode uniform in space, then nuclei excited in phase, would expect collimated x-ray emission (linear phased array effect)

•So, which nuclei are best candidates?

What are lowest energy nuclear transitions?

1.5 keV collimated x-rays in Karabut experiment (ICCF10,11)

Pinhole camera x-ray image of cathode

Interpretation and model

•Propose interpretation of Karabut experiment:

•Discharge turn off causes excitation of compressional vibrational mode

•Highly-excited mode couples to strongly-coupled nuclear transition

•Allows weakly-coupled transition in 201Hg to be excited

•In-phase excitation leads to phased-array effect collimation

•Consistent with Karabut experiment if 201Hg taken to be weakly coupled to oscillator, and second transition strongly coupled

•Can only get consistency for phonon exchange in association with nuclear configuration mixing

Proposed mechanism for excess heat production

•Need to arrange for highly excited vibrational mode

•Need to arrange for vacancies in Pd (or Ni, or other metals)

•Need to load to create molecular D2 (or HD) near vacancies

•Highly excited phonon mode plus interstitial D causes mixing of vibrational and nuclear (3S and 1D states) degrees of freedom

•If insufficient D, then highly excited phonon mode causes mixing of vibrational and nuclear (host Pd, Ni, etc) degrees of freedom

•D2 interacts to make 4He (or HD to make 3He), with energy to vibrational mode

•Need to remove helium (high temperature helps diffusion)

“Clean” vs “dirty” operation

•Operation with interstitial D and optical phonon mode excitation in the model results in little excitation of host nuclei, get 4He and little else

•Acoustic mode operation in the model results in mixing with host lattice nuclei to allow D2/4He and HD/3He transitions, but now can excite long-lived states that decay by disintegration

•So PdD (and other metal deuterides) can run “cleanly” based on optical phonon excitation in the model

•And NiH (and other metal hydrides) expected to run “dirty” based on acoustic phonon excitation in the model

•PdD (and other metal deuterides) can run “dirty” if acoustic phonon mode excitation used, but can get energy boost from induced fissions

Take away message I

•Large amounts of energy production observed in Fleischmann-Pons experiments

•Absence of commensurate energetic nuclear radiation indicates that fundamentally new physical process involved

•Only viable theoretical approach is for coherent energy exchange with quantum fractionation

•Karabut experiment seems to show effect in isolation

•Letts 2-laser experiment seems to show effect for excess heat production

Take away message II

•Theoretical models constructed which predict/explain coherent energy exchange with fractionation of large quantum

•Models require highly excited vibrational mode

•In Fleischmann-Pons experiment, molecular D2 transitions to 4He, energy goes into optical phonon models according to model

•In Piantelli experiment, molecular HD transitions to 3He, energy goes into acoustic phonon modes according to model

•Acoustic mode operation according to model leads to inadvertent excitation of long-lived fission unstable states of host nuclei, causing substantial induced disintegration (with energy loss in NiH, and energy gain in PdD)